Automatic power transmission



sept. 2s, 1'943.v H. RNER 2,330,375 1 AUTOMATIC PQWEB lILIRNSMISSONFiled May :51, 1941 4 sheds-sheet@ /NvEN-ron:

Sept. 28, 1943. H. QRNER AUTOMATIC POV-IER TRANSMISSION 4 Sheets-Sheet 2.Filed May 3l, 1941 NHHV/ l Sept. 28, 1943. H. ORNER 2,330,375

AUTCMATIG PowER TRANSMISSION 4 Sheets-Sheet 3 Filed May 3l, 1941 Sept.28, 1943. H. oRNER i AUTOMATIC POWER TRANSMISSION FiledMay :51, 1941'A 4sheets-sheet 4 Patented Sept. 28, 1943 AUTOMA'rIcPoWER 'rn'ANsMrssIoNHarry Orner, Cleveland Heights, Ohio Application May 31, 1.941,seriaiNo. 396,225

25 Claims.

This invention relates to power transmissions, and particularly todifferential gearing transmissions which are connected for powertransmission between a 'power source and a, driven load, and whichautomatically vary the speed ratio of transmission.

The invention is particularly applicable to .the driving of loads havingconsiderableinertia, t accelerate or slow down the load by a rotatingpower source such as an internal combustion engine` or electrical motor;and to cases in which it is desirable to have the speed Aof the loadincrease or decrease respectively as the torque of the load decreases orincreases, below or above a normal torque; and the invention comprisesmeans by which changes in the speed of the load are eiected by atransmission, the speed ratio of which varies automatically, in responseto changes of speed and to torque of the load.

The subject matter of this application is in part a continuation of thesubject matter of my copending application Serial Number 346,172,

filed July 18, 1940. l

The primary object of my invention is to provide anautomatictransmission that will automatically transmit power from adrive shaft to a driven shaft when the drive shaft rotates above apredetermined idling speed to cause the drive shaft to gradually speedup the driven shaft until a predetermined gear ratio is attained andthen' to automatically decrease the predetermined gear ratio toward orto a one to one ratio, and vice versa, and by which such changes are.effected smoothly, automatically and uninterruptedly, without thenecessity of shifting gears.

Another object of this invention is to provide a diierential geartransmission that will cause a.

driving shaft to be rotatably connected to a driven shaft at apredetermined velocity of the latter to drive the driven shaft at apredetermined 'gear ratio. I

Another object is to provide a diiferential gear transmission --thatwill automatically vary the ratio of transmission therethrough between adriving and a driven shaft responsive to changes of therelativetorquesor speeds of the shafts.

Another object is to provide a differential gear transmission havingimproved brake means for varying the ratio of transmission, and improvedmeans to variably, automatically apply the brake means. l

Another object is to provide a differential gear transmission havingimproved braking means for. varying the ratio of transmission,landwherein such brake means is automatically controlled responsive to thetorque-speed relations of the driving and driven shafts.

Another object is to provide a 'differential transmission having animproved braking means for retarding the gear trainas a unit, to causethe driving shaft to drive the driven shaft through an increased gearratio.

Another object is to provide a mechanism which may be disposed between asource of power and a load to function as a variable speed-ratio powertransmission to drive the load; or as a clutch to cushioningly co ectthe load to the source; or as a brake to cushioningly retard the load.

Other objects of my invention will become al)- parent from the followingdetailed description of embodiments thereof illustrated in theaccompanying drawings and particularly pointed out in the claims, suchdisclosed means being merelsr illustrative of the various mechanicalforms in which the principle of the invention may be embodied.

In the accompanying drawings;

Fig. lis a longitudinal, sectional viewv of an embodiment of myinvention and'showing `two similar units. one in elevation and one insection approximately through a rotational axis thereof;

Fig. 1A is a continuation of the left-hand .Side of Fig. 1 and beingfastened thereto by boltsas illustrated in part by Fig. 10;

Fig. 2 is a sectional view taken from the plane from the'plane 4f-4 ofFig. 2, illustratinga valve arrangement;

Fig. 5.is a fragmentary sectional view illustrating a one-way valve;

Fig. 6 is a view illustrating a means of loading a valve means atpredetermined positions thereof;-

Fig. 'l is a sectional view taken from the plane 'l-'l of Fig. l,illustrating a one-directional braking mechanism and relative parts;

Fig. 8 is a fragmentary sectional view taken from the planet-8 of Fig.'7 showing a one-way valve fora one-directional braking mechanism.

Fig. 9 is asectional view taken from the plane 9-9 of Fig. 1,illustrating a one-directional braking mechanism having automatic meansto cause a driving shaft to clutch a driven shaft:

Fig. 10 is a fragmentary sectional view taken from the plane I|0 of Fig.9 with the parts extended above the plane 9-9 of Fig. 1;

Fig. 11 is a fragmentary sectional view taken from the plane of Fig. 1Ashowing a governor construction of an automatic one-directional brakecontrol; A

Fig. 12 is a fragmentary view of the governor construction as shown inFig. 1A but in a position effected by centrifugal force;

Fig. 13 is a top plan view of Fig. 12;

Fig. 14 is a, fragmentary sectional view taken from the plane |4--I4 ofFig.v 9, illustrating braking means for controlling a rotor housing indirect drive;

Figs. 15 to 17, inclusive, illustrate another embodiment of my inventiondiffering from the foregoing in the respect that the rotor housing isself-contained, hermetically enclosed, and has another form o fvalve'construction;

Fig. 15, similar to Fig. 2, is va sectional view taken from the plane||5 of Fig. 16 of a transmission unit with parts broken away to showautomatic means therein;

Fig. 16 is similar to one unit of the transmission shown in Fig. 1, andis a sectional view taken from plane |6|6 of Fig. 15, showing mechanismtherein.

Fig. 17 is a fragmentary sectional view taken from the plane II-I1 ofFig. 16 showing a valve construction. f

Referring rst to Figs. 1 to 14, inclusive which illustrate oneembodiment of my invention, I have shown in Fig. 1, and in section, arotor housing A, and on a common axis with a similar rotor housing Bshown in elevation, both rotatably supported in a g'eneral housing G.Rotor housings A and B being similar in structure, it will be sucient todescribe rotor housing A in detail.

The rotor housing A, as illustrated in Figs. l, 4 and 5 is composed oftwo sections 2 and 3 1, and a center plate 4, fastened together by bolts5, see Figs. 2 and 3, thereby forming a hollow cylindrical rotor housingA, rotatably supported by anti-friction bearings 6 and l, respectively,mounted in apertures 8 and 9, respectively, of general housing G. Rotorhousing sections 2 .and 3 have axially extending hubs I0 and |I, re-

spectively, so machined as to t into the inner.

races of anti-friction bearings 6 and respectively, and retained thereinby threaded collars I2 and I3, respectively, on the threaded ends of thehubs I0 and Contained Within the rotor housing A is a differentialgearing P, preferably of the planetary type, and comprising a sun gearI1 in constant mesh with one or more planet gears I6, rotatable on thesame axis as, and rigidly connected to, a similar number of planet gears|9. Planet gears I 9 are in constant mesh with a second and smaller sungear 20. Sun gear I'I is integral with or connected to the rotatabledriven shaft I5, and

the sun gear 20 is integral with or connected to the rotatabledriveshaft I6.

Planet gears I8 and I9 are keyed together by keys 22 and rotatablymounted on stationary shaft 24 xed into rotor housing A, each shaftpassing through the rotor housing sections 2 and 3, and through thecenter plate 4, and having a head 25 on one side, and a nut 26 on theopposite side, and a pin 21 locking thenut 26 to shaft 24. Rotary motionsupplied by a source of power to turn drive shaft I6 in a clockwisedirection as viewed from the left end, tends to turn driven shaft I5 ina similar direction, the motion being transmitted by gear train P. Inthis illustrative instance, because of the difference in pitch diametersof the sun gears ILand 20, the gear train P transmits motion at areduced gear ratio to driven shaft I5 from drive shaft |6 andai; aproportionally increased torque. With drive shaft I6 rotating in theclockwise direction and driven shaft I5 having a load or torqueresistance,

-if the rotor housing A were free to rotate on bearings 6 and 1, itwould rotate in a counterclockwise direction and this is controlled by aone-Way braking mechanism to cause gear train P to turn in the clockwisedirection under certain conditions as will now be pointed out.

In Figs. 1, 7 and 8, the preferred one-way braking mechanism isillustrated, consisting of a gear |00mounted on the hub of the rotorhousing A in splines I0 and in constant mesh with an idler gear 0|rotatably mounted on a stationary shaft |02, xed in housing G. Gears|00-IDI are encased in a running t in h ousing G in such manner as toform a relatively liquid tight t to cause a pumping action on a quantityof fluid F disposed in the housing G through holes such as 16, andplugged by threaded plugs 11, as shown in Fig. 2; and similar plugs 18are provided at the bottom, see Fig. 1, for draining off the liquid whendesired. When air is used as a fluid instead of liquid as will bereferred to, vents may be provided in housing G, such as holes 16.

The gear |00, in this embodiment is rotated in 'a clockwise directionviewed from the left, see Fig. 7, as the rotor housing B tends torotate, and at the side of the gears |00- IUI where their teeth movetoward each other to intermesh, they project into the area |60 and areheresubmerged below the level of the liquid F. The gear |00, rotatingfreely in a clockwise direction, will force the liquid, by the pumpingaction. of the intermeshing teeth, outwardly into the area |60, but withno pumping load braking action to retard .gear train |00-IUI. Ininstances where this 'rotation of this gear train |00- 10| is of suchhigh relative speed as to cause the uid to exert a retarding actionbecause of their being submerged inthe liquid, the level of the liquidmay be maintained below the point of the intermeshing gears |00-40|;however as will be pointed out, part or the liquid F at normal operationof this transmission will be carried within the rotor housing A and Band bring the level to the desired position.

On the opposite side of the gears |00-IUI is an area |I3 into which themeshed gears pump uid when the gear |00 rotates in a counterclockwisedirection. A one-way valve I 03, see Fig. 8, is provided and soconstructed as to restrict 'any ow of liquid F from this area ||3 and toopen to permit flow of liquid to this area |I3. A suitable typecomprises a ball |04 seated on a machined surface 05 concentric with ahole |06 in housing G, and a, spring |01 abutting the housing G and uponball |04, and of such tension as to permit free ow of liquid F into thearea 3 but to cause the ball |04 to seat on the machined surface |05conforming to the ball |04 and prevent the now ofy liquid from this area3. The confined liquid will cause a pumping load back `pressure or loadon the intermeshing teeth of the gear train |00-IUI and retard anyilocity of the drive shaft I6.

braking mechanism is shown, wherein the direction of rotation of therotor housing A is controlled in both directions of rotation for thefollowing purposes.

If `the rotor housingA is permitted to rotate in' a/counter-clockwisedirection of rotation, the drive shaft I6 will rotate withouttransmitting rotary motion through the gear train 'P to th'e drivenshaft I5, and hence will effect a neutral or idling condition of thetransmission; and if the fluid F is properly throttled at the hole |06,the gear train ||0| willv be retarded causing the drive' shaft I6 tosmoothly transmit rotary motion thru the gear train P from no-drive tothe predetermined gear reduction ratio, analo- 'gous in action to theconventional foot clutch in the present day automobile, when shiftingfrom neutral to first. VTo this end a valve C is provided havinga`valvebody H0 with enlarged valve head III having an annular tapered surfacet0 fit into a valve seat H2. The valve seat H2 opens-into the housing G,see Fig. 10, and communicates with the area H3, and permits throttlingof the fluid F tocontrol the pump load braking action'of the gear train|00-|0|, to control the counter-clockwise rotation of rotor housing A.

The valve body H0 may be controlled in any desirable way, but it ispreferable tohave valve C controlled automatically responsive to apredetermined speed of the drive shaft I6. For such automatic control acylindrical chamber I|5 is provided concentric with valve head IIIforming an annular space H6 between the valve head I II andthe innerwalls of the cylindrical chamber H5, to permit a free flow of the fluidF, as pumped by the gear train |00-IOI, to pass thru an orifice in thecylindrical chamber `I I5, thence through the annular Space"||6 if belowa Predetermined rate of flow, as governed by the ve- This permits therotor housing A to rotate counter-clockwise and hence permits the driveshaft I6 to rotate independently of the driven shaft I5, therebyeffecting an idling speed of the shaft I6. However when the drive shaftis speeded up and reaches such velocity as to cause the gear train|00-IOI to pump` fluid F through the annular space H6 beyond thepredetermined idlingrate, pressure will be created on the valve head IIIto seat it on the valve seat H2, and so retard the circulation of fluidF, to thereby retard the gear train |00-|0|. A dash-pot Aconsisting of acylinder H8 fastened in the cylindrical chamber H5 and.

a piston H9 tted therein and attached on the other side of the valvebody H0 constitutes a control for the rate of movement of the valve headIII toward itsl valve seat H2 by the pressure of the fluid F on thevalve head III, the movement being governed by a lhole |20 in the.piston H9 to govern the rate of liquidescapement. A spring H1 abuttingthe piston H9 and the end wall of cylinder I I8, is provided to Opposemovement of the valve head III toward the valve seat |I2 and to opposeall pressures on the valve head Hl effected by the pumping num F, upltothe predetermined pressure by the restricted' ow through the annularspace H6. The area ofthe annular space H6 and the tension ofthe springH1 are predetermined by design to cause the valve` C to seat at apredeterminedrate of flow of fluid F as pumped by the gear train I00I0|;and dash-pot IIB-I I9 Vand its escapement at |20 predetrmine' the rateofthrottling of the valve C for smooth clutching of the rotary shafts.

Fluid F pumped by the gear train I 00-IOI above the predetermined ldlingrate will move the valve head III toward the valve seat I|2 at such rateas to throttle the circulating fluid F to cause it to gradually build upa pumping load in the area II3 and gradually retard the pumping gearAtrain I00'-|0.| until the valve C is completely closed and retainedclosed by the pressure therein. A one-way valve |03, see Fig. '1,asvdescribed for rotor housing B is similarly connected to this area II3 by the channelv |2I, see Fig. 9, and in all conditions in which valveC is closed the one-way valve |03 will function as described A for rotorhousing B, see Fig. '7.

The valve C, as pointed out, functions only during the transition fromneutral or no-drive or idling of the transmission, to the firstreduction gear ratio; at all other times it is desirable to have valve Cclosed'or so nearly closed that any pressure in area H3 willbemaintained and the following means is therefo-re provided.

`It may be borne in mindthat the driven shaft I5 at neutral or no-driveis not rotating, being independent of drive shaft I6; and this u alsothe condition at which valve C is'open.` Referring to Fig. 1A, and llto13, inclusive, a governor mechanism S is provided on'driven shaft I5,consisting of a collar |22 fastened to the shaft I5, a collar |23 freeto move longitudinally on the shaft I5, bosses |26 extending outwardlyfrom the axis on each of the collars to receive links |25 and links |26,on collars |22 and |23 respectively. Links |25 and |26 are fastenedtogether at their other ends by a pin |2' in such manner as to permitrelativev outward motion of the collar |23 longitudinally on the shaft I5 with respect to stationary collar |22 until it abuts a stop such as acollar |28 fastened to shaft I5, see Figs. l2 and A13. A spring |20 isdisposed between collars |23` and |28- with sufficient tension tonormally causecollar |23 to ,be in contact with collar |22, see Fig.1A.` Weights |30 are mounted on pin |21 in such manner' as to beeffected by centrifugal force upon rotation of the driven shaft I5, themovement of the weights radiallyoutwardly cause the links l|25--I2Ii tomove collar |23 toward collar |28 overcoming the tension of spring |29.A finger |3| contacting the movable .collar |23 is caused-to move withit, 'see Figs. lA and 10,

kand moves a shaft |32 fastened thereto, journaled inl housing G coaxialwith the valve body I I0 of the valve C and the piston I I9.

When the pumping gears I00-l-IOI are retarded by the pumped load brakingactionY as governed by the throttling of fluid F by valve C,

the driven shaft I5 will start to rotate, and the valve C will start toclose. When a predetermined speed of the shaft I5 is attained, the valveC will be closed and at this speed of the shaft I5 the weights |30 moveout to retain the valve C closed. When the velocity of the driven shaftfalls below the predetermined velocity the springs |29 -move the collar|23 to Contact collar |22 and release the valve C, andthe spring H1 ofvalve- C will movethe piston |20, the shaft |32 and -finger` I3I to theoriginal positions to be operated again when it is again desired tocouple drive shaft I6 to driven shaft' I5 through the planetary geartrain P, by againspeeding up the shaft I6.

Automatic means is therefore provided as described to change from theno-drive or,idling condition of my transmission, to the first gear thechange from this rst gear reduction ratio of the differential gearing Pto direct drive or one to one ratio of transmission by putting a brakeload on pinions I8 and I9 to correspondingly cause the gear train P torotate as a unit. It is desirable for the automatic means to do th'mresponsive to torqueV and speed differences as between the shaft I andshaft I6; and itis preferable to do this so that for an increased loadon the load shaft I5, the ratio of transmission will be reduced and thetorque correspondingly increased and vice versa. The torque resistanceor load o n the driven shaft I5 to be overcome, will determine theproper gear reduction ratio to .be provided to correspond With theparticular machine to be driven and the source of rotary power. In themechanism to be described, when the torque resistance has been overcomeand the load is started and speeded up to the predetermined speedreferred to at which it is driven at the reduction speed ratio, thespeed ratio of the transmission changes gradually to direct drive or oneto one ratio from drive shaft I6 to driven shaft I5. This isaccomplished by slowing down and 'nally stopping the rotation of theplanet gears I8 and I9 on their axes thereby causing revolution of thegear axes in unison with the sun gears I1 and 20 and rotary motion ofthe driveshaft I6 is thereafter transmitted in a direct drive, to drivenshaft I 5.

The differential gear train P contained Within rotor housing A andcomprising the sun gear in constant mesh with theplurality of equallyspaced planet gears I9 (two planet gears being illustrated see Fig. 2),has a running twithin machined apertures 35, for the planet gears I9 andaperture 36 for'the sun gear 20, and enclosed by the center plate 4which constitutes a transverse aperture wall. This fit is close enoughto be .liquid tight for liquids such as oil, to be referred to, andpermit little or no escape of such fluid between the Walls of theapertures the center plate 4 land the enclosed gears. It is, understoodthat a fit in this instance may be either a simple metal to metal t ormay be any of the more compound flts such as are provided by rings orpacking (not shown) to suit the conditions for which this invention isintended to be used. as will become apparent.

Referring to Fig. 2, -inlet channels 38 are pro-v vided, starting fromholes 39 in the center plate 4, see Fig. 3, and terminating on theperipheral walls of the apertures 35. In certain circumstances, aone-way valveA may be desired in channel 38, see Fig. 5, a suitable typecomprising a v ball 40 seated on a machined surface 4I concentric with ahole 39, and a spring 42 abutting upon,

the housing section 3and ball 40, and of such tension as to permit freeiiow of uid F into channels 38 but to cause the ball 40 to seat on themachined surface 4I conforming to the ball 40 and prevent the flow ofthe duid out of channels 38. Y

Teeth I S' on 4the gearl I9 mesh with teeth 20' on the sun gear 20, seeFig. 2.' On the side where teeth I9 and 20' move toward each other tointermesh, are pressure Vchambers 44, these pressure chambers 44 beingconnected together to equalize pressure therein, and in the instantembodiment this is effected by a diagonal groove in plate 4. Valvearrangements indicated generally at E-E, are each connected by an orice41 in rotor housing A' to aV pressure chamber 44V and an orifice 48 inplate 4, see Figs. 2 and 4, leads from valve E to a hallowed .4 andpasses the ball 40 of the one-way valve D, see Fig. 5, and ows throughthe channel 38 into the aperture 35 and is carried, by the spacesbetween the teeth I9' upon rotation of the planet gear I9, to thepressure chamber 44. At this point, teeth I9 intermeshing with teeth'20'of the sun gear 20, ca use the teeth to displace the uid F in the spacesbetween the teeth, and force it into the pressure chamber 44, causing arotary gear pumping action to occur on the uid F and urging the uid Ftoward the orifice 41. The orices 41 and 48 are so designed as to permitfree flow of the fluid F through the valve E, when completely open, atthe maximum rate of flow caused by the pump action of the gear teeth I9and 20'. A plug 49 is provided in the outlet orifice 48 having anopening 49 so proportioned as to begin to restrict the ow of uid F at avelocity just below the maximum rate of ow as determined by the speed ofthe gear I9 and 20, at which the change to a higher ratio oftransmission is to begin. Free unretarded rotation of the planet gearsI9 and 20 on their respective axes is therefore permitted until suchvelocity is reached at which theiiuid flow begins to be restricted bythe orifices 49 and cause` pressure thereby built up in pressure chamber44, to begin to retard the planet gears I9 on their respective axes andto cause the rotor housing A to start rotating.

The control of the fluid F as described is effected by the valvearrangement E, and this valve construction may be any design to suit anyparticular application. The valve E in the instant embodiment is shownin Figs. 2 and 4, and comprises a cylindrical valve body 54 with itslongitudinal axis lyingpreferably on a radial line from the axis of therotor housing A and mounted therein. The inner end of valve body 54 hasan enlarged circular valve head 55 with proper taper to lit the valveseat 55. Valve head 55 is concentric with orice 41 and is interposedbetween oriices 41 and 48 to control uid flow therethrough, and is freeto move longitudinally in a circular chamber 51, in rotor housingsection 3, concentric with valve head 55. The diameter of the chamber 51conforms to the diameter of the valve head 55 to permit it to movefreely outwardly from the valve seat 56 and to permit the iiow of uidthrough the orifices 41 and 48; and when moved inwardly tends torestrict Aand ultimately stop the fiow of liquid through orifices 41 and48, causing the liquid to be confined in' ressure chamber 44 and henceretard the rota ion of gears I9 as explained.

The lvalves E are operated automatically to open upon a relativeincrease of load shaft torque and eiect a decrease of transmissionratio, and to close and increase the transmission ratio upon a relativedecrease of load torque; and the dii-- ference between the drive shafttorque and driven shaft torque is balanced in correlation with thedifference between the drive shaft speed and the driven shaft speed; andthis is accomplished as follows.-

The valve body 54 is journaled in a cap 58 closing the chamber 51 andacting as a stop for the outward movement of the valvehead 55. The'outerend o f the valve body 54 is bifurcated to receive one 'end of a beammember 60 pivoted on a pin 8| in the rotor'housing A, and having at itsother end a weight 62. Apin 64 passes through the bifurcations of thevalve body 54 and through an elongated hole 65 in beam 60m chambers 44and 51 and as the prime-mover by similar continuous increment steps,overcomes the load.

such manner that motion can be transmitted v -gears I9--20, from thechamber 44, through orificev 41, into chamber 51, through orifice 48,into the hollow portion M of rotor housing section 2,v

the fluid passing freely through theorifice 49' ofthe plug 49 until'a-predetermined rate of flow of fluid is attained, approaching themaximum flow as governed by the velocity of the driving shaft I6. Beyondsuch predetermined flow rates restriction of the ow causes a pressure inthe chambers 4'4 and 51 which retards the gears I9 and causes the rotorhousing' A't" start turning at a speed to just cause the weight 62, bycen trifugal force, to overcome the initial tension of the spring 66 andpermit the valve head 55 to be moved toward the/valve seatv 56. Thiscauses a further increment of restriction of the flow of iiuid throughthe orices 41 and 48, and causes a further increment of increase in thepressure in chambers 44 and 51 and causes a further increment of speedof rotor housing A. Pressure in chambers 44 and 51 tends to move thevalve head 55 in a counter direction, to tend to increase .the now ofuid F. Hence two counterforces act on the valve E, the centrifugal forceof increased velocity acting on the weight end of the beam 6i); and theincreased fluid pressure in chambers i4 and 5l ,on the valve end of thebeam 60. The weight 62, lever arms of the beam $5, and spring 5S, are sodesigned as to overcome the pressure in chambers I4 and 5lproportionally as the prime mover on driving shaft I6 overcomes theresisting load on the driven shaft I5. ,Y

' The fluid pressure in chambers 44 and 51 increases as the load ondriven shaft I5 increases in relation to the torque of the prime-moveron the driving shaft i6; and decreases as the torque of the prime-moveron driving shaft I6 overcomes the load on the driven shaft I5. Hence asthe weight 62 causes the valve E to close in continuous increment steps,the prime-mover on the driving shaft IG tends to overcome the load ondriven shaft I5 in similar continuous increment steps until the valvehead 55is completely seated on valve seat 56 and stops all flow of fluidF and the drive shaft I6 drives the driven shaft I5 in one to one ratio.At any time during operation, if the load is increasedon the drivenshaft I5 in relation to the torque of the prime-mover on the drivingshaft I6, pressure in chambers 44 and 51increalses to unseat or furtherunseat the valvehead 55 to permit fluid flow to relieve the pressuretherein and at the same time permitting the gears to rotate, andpermitting the driving shaft I6 to drive the driven shaft I5 at anincreased gear reduction ratio, to overcome this increased load, and bycontinuous incre- A transmission is therefore provided that starts froman idling speed of driving shaft I6 and automatically causes the-drivingshaft I6 to become drivingly engaged with the driven shaft I5 in asmooth continuous manner upon increase of velocity of the drive shaftI6; and

the driven shaft I5 is speeded up until it is driven at a predeterminedgear reduction ratio; and the predetermined gear reduction ratio is thensmoothly and continuously decreased automatically, as the` driving shaftovercomes the load on the driven shaft, until a one to one ratio isattained; and these conditions reverse automatically to give anincreased gear reduction ratio if the load increases relative to thedriving torque.

In this transmission as pointed out the torque is balanced againstrotary speedy in a direct man.- ner to suit the particular application,but in cert'a'n nstancesfthe torque may not be in such direct relationsand'the lever beam 6l! f'rlist' be' properly loaded at definite pointsof torque to compensate such variations. Referring to Fig. 6, which is aview showing an example of such loading, a compression spring 61 in acylinder 6i! abutsa member 69 at an initial tension in such manner as toload the lever arm of beam 6I! at a predetermined position; or a springsuch as 16 may be used, on a pin 'II with one end abutting a pin I2 andthe other end 14 extending lbeyond a stop pin 13 at an initial tensionto engage with a lever arm of' beam 66 to load the lever arm at apredetermined position relative to the torque value at that instant. Anysuch springs /cr similar constructions may be used in one or more placeson the beam E@ to give the proper relation of the movement of the beamsllwith the variations of the speed of the primemover overcoming theload. In certain instances the weight 62 may be dispensed with andpressure in chambersl 44 and 51 may act counter to a spring pressuresuch as spring 1U, to give a desired torque value independently of thevelocity transmitted.,

The rbtor housing rotates counter-clockwise as viewed from the left inFig. l, for the neutral or no-drive condition of the transmission, andwould tend to pump fluid in chamber 44 and also effect the weight 62 bylcentrifugal force. The

v counter-clockwise rotation of rotor housing A ment steps, until thevalve E is completely closed and the one to one ratio attained.

lchambers 44 and 51 will decrease permitting the valve head 55 to seatby continuous increment steps as the weight 62 overcomes the pressure inmay be loaded to -remain in ineffec takes place at a relatively lowvelocity since this is the condition at which the prime-mover idles,5and restriction 49' therefore permitsv free flow of the liquid F,because the gears' l926 rotate at a correspondingly slow speed. The beam60 e position by the initial tension of spring 66 to keep the valve Eopen at this relatively slow speed-` It may be desirable to control theclockwise 4 rotation of the rotor housingas viewed from the left, tocorrespond to the action of theconventional transmission of anautomobile when going down hill, wherein the conventional transmissionis shifted to a lower speed toact as a brake on the driven wheels byvcompression in the cylinders of the motor.- In the instant embodimentwhen used as an automobile transmission the braking of the rotor housingA or Bq or both would cause the transmission of rotary power from thewheels to drive the shaft I6 through the gear train P at an increasedgear ratio or overdrive ratio, to overcome the compression in thecylinders of the motor. and so retard the speed of the automobile.

To effect this, instead of the area |60 of Fig. 7, a chamber |50 may beprovided, see Figs. 9 and 14, in one or both of the units, having anoutlet I| to permit free flow of uid F. A'valve |52 coacting with avalve seat |53 in the outlet |5I Will then control the fluid iiow asdesired, to control the pump load pressure in chamber |50, to cause abraking of the clockwise rotation of the rotor housing A, to cause theshaft I5 to drive the shaft I6 at an increased gear ratio through thegear train P. Any retarding force on the shaft I 6 would retard therotar-yshaft- I5.,

It-follows' furthermore that the transmission above described may beused as an overdrive transmission. 'Ihe driven shaft in this case I 6will be driven at an-increased speed ratio from the driving shaft I5.Thus if a prime-mover rotated the shaft I5, see Fig. 1, it wouldtransmit rotary motion thru the gear train P to the shaft I6 at anincreasing gear ratio upon retarding the clockwise rotation of the,rotor-housingrA:" At

normal conditions, the shaft, I5 would transmit rotary motion to shaftI6 through rotor housing A at one to one ratio, because of the increasedratio of transmitting rotary power through the diierential gear train P.Upon retardlng the rotor housing A by such valve means as ISI-|52, therotary power would be transmitted thru the increasing gear ratio of thegear train P to cause the shaft I5 to drive the shaft I6 at anincreasing speed, and such changewould be eifected smoothly and with nointerruptions.

The above described use-of my invention for overdrive can beautomatically controlled by using the valve construction C in place ofvalve means ISI-|52, to effect such change of overdrive at a definitevelocity of the rotary housing A. to effect a smooth continuoustransition from one to one ratio to the predetermined increased gearratio of the gear train P.

As to the general circulation of Kiiuid F in the mechanism describedabove the uid F is free to enter the rotor housing A and B between thevertical Walls in section 2 and plate 4, through openingsl 80 as shownin Figs. 2 and 3. A depending wall 96,.at the outer circumference of theopenings-80 forms a channel 91, U-shaped in cross-section, see Fig. 4,which retains the liquid therein by centrifugal force when the lrotorhousing A starts to rotate. These channels 91 are connected by a commonchannel so as to permit the liquid F to distribute itself equally in thechannel 91 for maintaining the dynamic balance. In the instantembodiment, the common channel is in the form of an annular under-cut98, see

Y Figs. l and 4. passing just outwardly of the planetgear |3'andconnecting channels 91 together by a common conduit path M. The holes 39of the inlet channels 38 communicate with this conduit path M, see Fig.5, and are continuously coveredi by liquid F as 'the rotor Vhousingstarts rotating.'4 The liquid F is caused to ilow through holes 39, intoinlet channels 38, see Fig. 2, by the pumping action of gear teeth I9'and 20', and to the pressure chamber 44. through the open valve E intothe annular path M, in a continuous cycle, to effect completecirculation of liquid F.

The intermeshing teeth I9' and 20' may cause some of the liquid F to belocked in the' space between the teeth, and a groove 50, see Fig. 2, incenter plate 4, is so placed as to relieve the liquid F into pressurechamber 44. Also agroove 5| is providedf in plate 4, from the channels38 to permit liquid F to reach the intake side of the gears I9 and 20.

When the rotor housing A is stationary and rotary motion is transmittedthrough the gear train P, liquid F, see Fig. 3, lies in the rotorhousing A, and in housing G, up to the level governed by the holes 16,see Fig. 2. 'Ihe liquid will be forced by the sun gear I1 into theconduit path M in a circular swirl, in the clockwise direction, as shownin Fig- 3. Near the planet gear I8 at the zone indicated by 99, theconduit path is restricted to the size of ,the undercut 98, and theplanetgear I8 4at these zones moving counterclockwise, moves the liquidF back into zone 99, causing the liquid F to accumulate atthe zone 99for supplying the inletiholes 39. This action decreases as the rotorhousing A starts to rotate, causing the liquid F, by centrifugal force,to iill the channels 91 up to the depth permitted by the depending wall95, see Figs. 4 and 5, and

tof the gear train P before the proper compression is formed in pressurechamber 44 to retard the rotation of the planet gears I9. Liquid may bepreferable in low speed units, in which the change-over to direct driveis required in a smaller number of revolutions of the sun gear 20.

In Figs. 15 to 17, inclusive, is another embodiment of my inventionsimilai to the embodiment described but different in respect to thevalve arrangement E, which is in this case constructed so as to permitthe rotor housing to be hermetically sealed and self contained.

The rotor housing A', is completely closed. and preferably hermeticallysealed; and the liquid F is conned to the rotor housing A'; and liquid Fhas a complete conduit path for free circulation and a conduit path fordynamic balance therein/as described for the rst form: hence thevertical walls of the rotor housing section 2 and center plate .4 willbe without any openings such as Figs. 2 and 3. Threaded plugs |35, seeFig. 15, tapped into vertical wall of rotor housing section 2 providefor adding liquid F, and these plugs |35 may be vented if air is used asthe fluid.

The valve consists of a cylindrical valve body |36 having a denite mass,fitted into a cylindrical chamber |31 in rotor housing A', lyinglongitudinally on an axis preferably radial from the axis of the rotorhousing A'. 'I'he valve body |36 has an annular beveled edge |38 on itsouter end.A

forming a valve head, to co-act with a valve seat |39 in the upper endof chamber I 31. 'I'he valve seat is retained in place by a pin |40, anda threaded cap |4| closes vthe outer end of the chamber |31 in the rotorhousing A. An orifice |42 in *the valve seat |39 communicates with apassage |43 leading to pressure chamber 44. An outlet orifice 48, seeFig. 16, in the plate 4, leads from the chamber |31. The valveconstruction |38-I39 is interposed between the orices |42 andD 48, tocontrol the rate of liquid F ilowing therethrough.

.A spring |44 abutting the valve body |38 and the cap Hi with an initialtension thereon, retains lthe valve body |36 in a position to permitfree iiow of liquid F. through orifices |42 and 43. This forms aAdefinite mass, to be acted upon by the centrifugal force of the rotationof the rotor -housing A', and to be urged radially downward take .up aposition corresponding to the torque on the drive shaft I6 and speedofthe rotor housing A', `to drive the load on the driven shaft l5, thevalve restricting the iiow of liquid F, to .cause a pressure in chamber44, to retard the gears I9, to cause the gear reduction ratio todecrease, as the torque overcomes the load.

Embodiments of my invention may be used with any form of differentialgearing, and ininstances where the form of differential gearing has therotor housing'rtating initiallyat the predetermined gear reductionratio, the plug t9 may be dispensed with since centrifugal force wouldact immediately on the weight 62 or mass of valve body |36.

My invention as described hereinbefore may be applied to various uses.For example, it may be used as a speed changing transmission between themotor and the propeller shaft of an automobile. In this instance, thegear reduction ratio through the differential gears would be such as tocorrespond to the gear reduction ratio oi the usual gear shifttransmission at low speed. In this use of my invention when the throttleis opened causing the motor to run above a predetermined idling speed,the propeller shaft is rotatably driven at a predetermined gearreduction ratio; and the vehicle will be started and brought up totravel at a rate governed by this predetermined gear ratio; and as thevehicle -inertia is overcome more and more, the predeter-1 mined gearratio will be gradually and automat-- ically reduced; and finally thevehicle will be driven directlytwithout gear reduction.

Conversely the transmission ratio will automaticallyand gradually bechanged to a gear reduction ratio in the event that the vehicleloadbecomes greater as when climbing a hill.

Y Again, the transmission above described may be utilized to perform thefunction of a clutch between any driven element and driving element, tostart the driven element from rest and bring it up to speedwithoutshock, particularly when the load being driven has considerablein.- ertia.

Again, the transmission above described may be utilized to perform thefunction of a brake to 'slow down a load being driven.

Again, the transmission'above described may be utilized to perform thefunction of an overdrive to cause the speed of an element to beincreased from that of a direct drive to that of an increased gearratio.

In' numerous respects, as lwill be apparent, my

invention is not limited to the exact details of constructionillustrated and-described.` Changes and modifications may be made,without departing from the spirit of my invention and withoutsacrificing its advantages, and my invention is comprehensive of allsuch modifications and changes which come within the scope of theappended claims.

I claim:

1. In a power transmission, a driving and a driven rotary shaft,interconnected through a differential gearing mechanism comprisingrotatable meshed gears, means tocontrol the rotary direction of thedifferential gearing mechanism responsive to a predetermined velocity ofthe Adrive shaft, to cause the drivingshaft to drive the driven shaft bythe' gears at a predetermined gear ratio, uid disposed to be pumped bymeshed teeth of gears of the differential mechanism tothereby exerta'pump load braking action on the pumping gears, and means to varia'-bly controlthe rate of pumped fluid flow tovar- ,iably gntrol the pumpload action, to variably control the ratio' of transmission, saidvarablecontrol means operable responsive to a relation.

of torque transmitted.

2. In a power transmission, `a driving and a drivenshaft, interconnectedthrough a differential gearing mechanism 'comprising rotatable meshedlgears, means to variably brake the rotary motion ofothe differentialgearing in a direction to cause the driving shaft to drive the drivenshaft by the gears at avpredeterminei gear ratio, said means operableresponsive to a predetermined velocity of the driving shaft, a fluidpumping mechanism co-acting with' said differential gearing mechanism,fluid disposed to be pumped therein to exert a pump load braking actionon the co-acting pumping mechanism and means to variably control thepumping load action, to variably control the' rate of transmission, saidvariable control means operable responsive to a relation of torque andHvelocity transmitted, l j

3. In a power transmission, a. driving and a driven rotary shaft,interconnected through a differential gearing comprising rotatablemeshed gears, means to variably brake the rotary m0- tion of thedifferential gearing in a direction to cause the driving shaft to drivethe driven/shaft by the gears at a predetermined gear ratio, fluiddisposed to be pumped by meshed teeth of gears of the differentialmechanism to thereby exert a pumped load braking action on the pumpinggears and means to variably control the rate of pumped fluid flow tovariably control the pump load action, to variably control the rate oftransmission, said'variable control means operable J responsive to arelation of the nuid pressure relative to the torque difference of thedriving and driven shafts and a centrifugal force relative to thevelocity transmitted.

4. In a power transmission, a driving and a driven shaft, interconnectedthrough a differential gearing comprising rotatable meshed gears, meansto variably brake the rotary motion of the differential gearing in adirection to cause the driving shaft to drive the driven Kshaft by thegears at a predetermined gear ratio, said -means operable responsive toa predetermined velocity of the driving shaft, iiuid disposed to bepumped by meshed teeth of gears of the dierential mechanism to therebyexert a pumped load braking action on the pumping gears and means tovariably control vthe pumped fluid to variably control the pump loadaction, to variably control the rate of transmission, -said variablecontrol means operable responsive to a relation of torque and velocitytransmitted.

5. In a power transmission, a driving and a driven rotary shaft.interconnected through a tard the rotation of the rotor variahly changethe rate d-ierential gearing comprising rotatable meshed gears, means tovariably brake the rotary motion of the dierential gearing in adirection t cause the driving shaft to drive the driven shaft by thegears at a predetermined gear ratio, said means operable responsive to`a predetermined velocity of the driving shaft, uid disposed to be pumpedby the meshed teeth of the gears of the differential mechanism tothereby exert a pumped load braking action on the pumpirg gears andmeans to variably control the rate of pumped fluid to variably controlthe pump load action, to variably control the rate of transmission, saidsecond means comprising a valve mechanism operably affected by arelation of pumped fluid pressure commensurable to the torque-diference' of the 4driving andTlriVh" shafts.'

6. In a power transmission, a driving and driven rotary shaft,interconnected through a differential gearing comprising rotatablemeshed gears, a fluid pumping mechanism coacting with said differentialgearing, fluid disposed in said pumping mechanism, means to throttle thefluid responsive to a predetermined velocity of the fiuid pumpedztlo.progressively ,cause-abrakeioad action' of theidifferential gearing' ina'direction of rotation to cause the driving shaft to drive the drivenshaft by the gears at a predetermined gear reduction ratio, fuiddisposed to be pumped by,meshed teeth of gears of the differentalgearing to thereby exert a pumped load braking action on the pumpinggears, means to variably throttle the rate of pumped fluid now tovariably change the pump load braking action to variably change theratio of transmission, said throttling means comprising valve meansoperably responsive to a relation of torque and velocity. transmitted.

'7. In a power transmission, a Adriving and a driven shaft,interconnected through a differential gearing comprising rotatablymeshed gears,

and movable by the uid pressure to further restrict the fluid flow and adash-pot on said valve to govern the rate of restriction toprogressively retard the pumping 'mechanism, to progres sively retardthe rotary housing, to progressively cause the driving shaft to drivethe driven shaft by the gears and pinions at a predetermined gear ratio,

9. In a power transmission, a power drive shaft and a driven shaftinterconnected through a differential gearing comprising a rotaryhousing rotatably supporting pinions and rotatable gears meshed withpinions, a, fluid pumping mechanism coacting with said rotary housing,fluid disposed in said means idvariably controlthe uid'ilow responsiveto a predetermined fiu'id pressure relative to the velocity of thedriving shaft and thereafter control the rate of fluid flow toprogressively retard the pumped uid and correspondingly retard thepumping mechanism, to progressively retard the rotary housing,Y toprogressively cause the driving shaft to drive the driven shaft by thegears and-pinions at a predetermined gear ratio...

10. In a power transmission, a power drive shaft and a driven shaftinterconnected through a differential gearing comprising a rotary hous--ing supporting pinions and rotatable gears meshed with pinions, a fluid.pumping mechanism co-acting with said rotary housing, means providingan orifice, a quantity of fluid disposed a rotorvhousing enclosing saidgears, a second gearing comprising a gear and an idler pinion, the gearbeing rotatable with the rotor housing and meshed with the idler pinion,uid disposed to be pumped by meshed teeth of the second gearing tothereby exert a pumped' load braking action on the pumping gears, meansto variably throttle the fluid responsive to the predetermined velocityof fluid pumped, to variably rehousing in a direction to variably causethe drive the driven shaft by the differential gears at a predeterminedgear reduction ratio, iiuiddisposed to -be .pumped by meshed teeth ofthe differential gearing to thereby exert a `pumped lead braking actionon the pumping gears of the differential gearing, means to variablythrottle the rate of pumped uid flow ro variably change the pump loadbraking action, to of transmission, said second throttling meanscomprising valve means operable responsive to -a relation of torque andvelocity transmitted.

8. In a pnwer transmission,A a power drive shaft and a driven shaftinterconnected through a differential gearingr comprising a rotaryhousing rotatably supporting pinions and rotatable gears meshed withpinions, a uid pumping mechanism -co-afcting with said rotary housing,Huid disposed in said pumping mechanism,

.means to variably control the fluid flow comprising a valve in the pathof the fluid to restrict the fluid new at a predetermined fluid pressuredriving shaft to to i be pumped by the pumping mechanism through theorifice at pressure commensurable with the pumping mechanism velocity,means operating responsive to a predetermined fluid pressure toprogressively retard the pumped fiuid.` to correspondingly brake therotation of the rotary housing at a predetermined rate, to progressivelycause the driving shaft to drive the driven shaft by the gears at apredetermined gear ratio. A

11. In a power transmission, a, power drive shaft and a driven shaft,interconnected through a differential gearing comprising arotary housingrotatably supporting pinions and rotatable gears meshed With pinions, asecond gearing comprising a gear and an idler pinion, the gear beingrotatable with the rotary housing and meshed with the idler pinion,means providing an orifice, a quantity of fluid disposed to be pumped bythe rotating gear and idler pinion through the orifice, at pressure'commensurable with the gear and idler pinion rotary velocity, meansoperating responsive to a predetermined fiuid pressureto progressivelyretard the differential gearing mechanism comprising a one-waybrake androtatable meshed gears. to cause the driving shaft to drive the drivenshaft z at a predetermined gear ratio, a fluid disposed to be pumped bymeshed teeth of the gears of the differential mechanism to thereby exerta pump load braking action on the pumping gears and means to variablycontrol the rate of pumped fluid now to variably control the pump loadbraking action to .variably control the ratio of transmission, saidmeans being operable responsive to a. relation of torque and velocitytransmitted.

pumping mechanism,

13. In a differential power transmission a pair of differential gears,pinions meshed with the gears, a drive shaft connected to one gear, adriven shaft connected to the other, a one-way brake provided wherebypower is transmitted from one shaft to the other at a predetermined gearreduction ratio eected by relative rotation of the gears and pinions, apumping mechanism -coacting with said pinions, a fiuid conduit pathcontaining fluid disposed to be pumped therethrough by the pumpingmechanism, means to progressively increase the fluid pressure at thevthe differential mechanism to thereby exert a pump load braking actionon the pumping gears and means to variably control the rate of pumpedfluid flow to variably control the pump load braking action to variablycontrol the ratio of transmission, said means being operable responsiveto a relation of fluid pressure commensurable to the torque-differenceof the driving and driven rotary shafts,

15. In a power transmission, 'a power drive shaft and a driven shaftinterconnected through a differential gearing mechanism comprising aone-way brake to cause the drive shaft to drive the driven shaft by thegears through the differential gearing mechanism at -a predetermined`ratio, a fluid disposed in a fluid circuit including two intermeshedgears toexert a pumped loadA braking action om the gears comparable tothe torque-difference of the drive and driven shafts and means providedto control the pumped fluid to variably control the differential gearingmechanism to variably control the rate of transmission.

16'. In a power transmission, a driving and a driven rotarys shaft,interconnected through a differential gearing mechanism comprising aone-way brake and rotatable meshed gears, to

cause the driving shaft to drive the driven .shaft at a predeterminedgear ratio, a fluid disposed to be pumped by meshed teeth of the gearsof the differential mechanism to thereby exert a pump load brakingaction on the pumping gears and means to. variably control the rate ofpumped fluid flow to variably controll the pump load action to variablycontrol the ratio of transmission, said means being operable responsiveto a relation of torque difference of the driving and driven shafts andvelocity transmitted. v

17. In -a power transmission, a driving and a driven rotary shaft,interconnected through a differential gearing mechanism comprising aone-way brake and rotatable meshed gears. to cause the driving shaft todrive the driven shaft at a predetermined gear ratio, a fluid disposedto be pumped by meshed teeth of the gears of the differential mechanismto thereby exert a pump load braking action on the pumping gears andmeans to variably control the rate of pumped uid flo'w to variablycontrol the, pump means responsive to a balance of predetermineddiiierential gearing mechanism `drive shaft, a rst differentialgeardriventhere' load action tovariably control the ratio',n of

transmission, said means being operable respon.-

sive to a relation of the uid pressure relative to the torque differenceof the driving and driven shafts and a centrifugal force relativejtovelocity transmitted.

18. In a power transmission, a

rotatable meshed gear and pinions, a quantity of fluid to be pumpedunder pressure by rotation of the meshed gear and pinionsand movablepumped iluid Apressure and centrifugal forcev of the velocitytransmitted for progressively con-W I trolling the ow of pumping fluidto progressively increase the uid pressure, to progressively brake therotation of the pinions.

19. In a differential power transmission, la including. a

by, a second differential gear and a driven shaft driven thereby,pinions meshed with both gears, a brake on an element of thedifferential mechanism to prevent its rotation in one direction wherebythe drive shaft may drive the driven shaft by the gears at apredetermined gear reduction ratio, fluid disposed to be pumped by theteeth of the gear and pinion meshed enl gagement, at pressurecommensurable with the speed of the driven shaft, to thereby exert apumpv load braking action on the pumping pinions, means for throttlingthe flow of pumped fluid to increase the pump load to retardrotat'ion'of the pinionsV and change the ratio Vof transmission, meansoperably affected by a relation of decreasing fiuid pressurecommensurable to)v the decreasing torque difference of the driving anddriven shafts and increasing centrifugal force commensurable to thetransmitted.

20. In a differential power transmission, a differential gearingmechanism including l a drive shaft, a first differential gear driventhereby, a second differential gear and a driven shaft driven thereby,pinions meshed with vboth gears, a brake on an element of thedifferential mechanism to prevent its rotation in one direction wherebythe drive shaft may drive the driven shaft by the gears at apredetermined gear reduction ratio, fluid disposed to be pumped by theteeth of the gear and pinion meshed engagement, at pressurecommensurable with the speed of the driven shaft, to thereby exert 4apump load braking action on the pumping pinions, means forvcontrollingthe ow of pumped fluid to increase the pump load to retard rotation Voi'the pinions and change the ratio of transmission, said means comprisingvalve means operable'by relation of uid pressure commensurable to thetorque transmitted.

21. In a differential power transmission, a dierential' gearingmechanism including a drive shaft, a first differential gear driventhereby', a second differential gear -and a driven shaft driven thereby,pinions meshed with both gears, a brakei-on an element ofthe'differential mechanism to prevent its rotation in one directionwhereby the drive shaft may drive the driven shaft by the 'gears at apredetermined ratio, fluid disposed to be pumped by the teethA of thegear and pinion meshed engagement, at pressure; commensurable with thespeed ofA the driving'yand a driven rotary shaft, interconnected ataprede-l said means comprising' valve,-

increasing velocity,`

driven shaft, to thereby exert a pump -load braking action on thepumping pinions, means forl of diierential gears, pinions meshed withthe gears, a drive shaft connected to `one gear, a driven shaftconnected to the other gear, a brake on an element of the differentialmechanism to prevent its rotation in one direction whereby power istransmitted from one shaft to the other at a predetermined gearreduction ratio effected by relative rotation of the gears and pinions,a fluid conduit path containing fluid disposed to be pumped therethroughby rotation of the gear and pinio'ns, a valve for controlling the ow,means to progressively close the valve operable by pumped uid in counterrelation to centrifugal force affecting the mass of said means, toprogressively increase the -uid pressure at the gear and pinions, toprogressively brake rotation of the pinions to thereby progressivelyreduce the degree of gear reduction of the transmission.

23. In a power transmission, a power drive shaft, a driven shaft, adifferential gearing mechanism comprising a one-way brake, relativelyrotatable pinions, for transmitting drive shaft power to the drivenshaft at a predetermined gear ratio of transmission effected by relativerotation of the pinions, means providing an orifice, a quantity of uiddisposed to be pumped by the rotating pinions through the orifice, atpressure commensurable with the pinion rotary velocity said oricerestricting the fluid flow at a predetermined uid pressure toprogressively retard the pumped fluid and correspondingly initiatingbraked rotation of the pinions, and means to further progressively brakerotation of the pinions responsive to uid pressure in counter relationto centrifugal force on the said means.

24. In a differential power transmission, a differential gearingmechanism including a I drive shaft, a first differential gear driventhereby, a second differential gear and a driven shaft action on thepumping pinions, means for controlling the flow of pumped uid toincrease the pump load to retard rotation of -the pinions and to changethe ratio of transmission, said controlling means comprising valve meansoperable commensurably with a. predetermined pressure. and thereafteroperable responsive to variable uid pressure'in counter relation toVariable centrifugal force on said means commensurable 'with thevelocity transmitted.

25. In a differential power transmission, a differential gearingmechanism including a drive shaft, a first differential gear driventhereby, a second differential gear and a driven shaft driven thereby,pinions meshed with both gears, a brake on an element of thedifferential mechanism to prevent its rotation in one direction wherebythe drive shaft may drive the driven shaft by the gears at apredetermined gear reduction.ratio, fluid disposed to be pumped bymeshed teeth of the gear and pinions at pressure commensurable with thespeed of the driven shaft to thereby exert a pump load braking action onthe pumping pinions, means for controlling `the ow of pumped iiuid toincrease the pump load to retard rotation of the pinions and to changethe ratio of transmission; said throttling means comprising valve meansoperable commensurably with a predetermined pressure,

. and thereafter operable responsive to variable uid pressure actingupon the valve means to permit ow of uid, and a variable centrifugalforce acting on the mass of the valve means to retard owof uid. i

HARRY O RNER.

